Don't know what lot of Unique was used for the VMD in Lee's load table but I think the Unique info is a mistake. If you figure the VMD of Unique powder as per Lee's instructions you get a VMD# 25 or 30% larger. I know cuz I had the same Q's as the OP and calculated the VMD's from two lots of Unique from two different 8 lb jugs and they came out virtually the same.

Regret that I don't have the figures as I gave my Lee stuff to my son, but my calculated VMD was what I used thereafter and it produced drops that were a lot closer to those expected. The instructions for calculating the VMD's are right in the reloading data pamphlet. Check it out.

edit: thought I'd add that at that time I also calculated the VMD's for 231, 700x, 2400, etc, including a couple of rifle powders and the VMD's came very close to Lee's numbers. Unique info IMO is an error.